It is not just the chocolate bars and the potato chips,childhood obesity has its roots in variants of three pre-disposing genes,a study conducted among 3,000 city school children has found.

It is not just the chocolate bars and the potato chips,childhood obesity has its roots in variants of three pre-disposing genes,a study conducted among 3,000 city school children has found.

The study was conducted by researchers of AIIMS and Institute of Genomics and Integrative Biology (IGIB) on students between the ages of 11 and 17 years. It has been published in the journal Diabetes,published by the American Diabetes Association.

The children belonged to both upper and lower socio-economic groups and were examined for 25 genes,which were expected to be associated with obesity.

The association of genes has been examined for adult obesity. For childhood obesity we have very little knowledge of specific pre-disposing genes. We tried to examine 125 variants of the 25 genes that could be responsible for causing inflammation in the body, said Dr Nikhil Tandon,professor at Endocrinology department,AIIMS.

Authors detected three genes  IL6,LEPR and PBEF1  that have a significant role in to childhood obesity. These three genes,the study found,are distinct from the pre-disposing genes among the European population.

Dr Dwaipayan Bharadwaj,scientist at IGIB,who performed the genetic analysis for the study,said: There are studies globally on genetic profiling of childhood obesity. We have identified variations in three genes,that we can say are strongly associated with chronic inflammation that leads to obesity in young students.

The study pointed out that two variations in DNA sequences,found to be responsible for obesity in Greek and French children,have no impact in Indians. Similarly,the variations detected in Indian children were not found in the European studies.

Dr R K Marwaha,from the Institute of Nuclear Medicine and Allied Sciences,also participated in the study. There are significant ethnic variations,at the level of genes,in association with obesity, he said.

The genetic make-up of the participants was analysed at IGIB,to detect DNA sequence variations present in the obese and over-weight children. The physical manifestations of these variations were analysed for body mass index,height,weight and waist and hip circumference.

We have also identified for the first time,a dosage pattern in the genes  more the number of the identified genetic variations,higher the chance of obesity in the child, said Dr Bharadwaj.

As per the study,the role of environmental factors in controlling obesity cannot be ruled out,but if a child has any of the variations in these three genes the likelihood of obesity is heightened.

As an obvious corollary,controlling obesity will also be more difficult for those who have these pre-disposing genes, Dr Tandon said.